In certain types of galvanic dry cell batteries, such as the so-called alkaline type, the battery construction generally consists of a metallic casing or container (usually a suitable steel), an annular mass or mix of cathode material (e.g., a molded mixture of MnO.sub.2 and graphite) in the casing, a separator membrane (e.g., a paper liner) on the inside surface of the annular molded cathode mix, and an electrolyte as well as an anode material (e.g., a zinc powder) in the form of a central anode core within the separator membrane.
The casing is generally cylindrical, is closed on one end, and is initially open at the other end for receiving the internal components and materials. Good physical contact between the cathode mix and the casing is required so as to provide the proper electrical conduction which is critical to battery performance. Consequently, it would be desirable to provide an improved method and apparatus for the manufacture of a dry cell battery which would result in good physical contact between the cathode mix and the surrounding surfaces of the casing. Further, it would be beneficial if an improved method and apparatus could efficiently provide good contact between the casing and cathode material on a consistent basis in high speed production operations.
The initially closed, circular end of the dry cell battery casing is typically provided with a positive terminal in the form of a centrally located flat contact region or an outwardly projecting and generally circular deformation, bulge, pip or the like for engaging the positive contact in an electrically operated device. The central anode core of the completed battery is generally disposed so that it is coaxial with the projecting terminal in the casing end wall. However, the anode material does not directly contact the interior surface of the terminal or the surrounding interior surface of the casing end wall owing to the presence of the separator membrane end which surrounds the end of the anode material. Also, in typical constructions, there is usually some cathode mix sandwiched between the casing end wall and the separator membrane end.
The presence of the cathode mix between the separator membrane at the end of the anode core and the end of the casing does not contribute substantially to the electro-chemical process. Consequently, this type of conventional dry cell battery does not efficiently utilize the portion of the cathode mix which is typically present in the space between the end of the anode core and the casing end wall, including inside the terminal. Thus, it would be advantageous to provide an improved method and apparatus for minimizing the presence of the cathode mix between the anode core and casing end wall during the manufacture of the dry cell battery.
The amount of cathode mix in the dry cell battery depends upon the density of the cathode material and on the volume in the dry cell battery casing that is occupied by the cathode material. Accordingly, it would be beneficial to provide an improved method and apparatus for the manufacture of a dry cell battery wherein the density of the cathode mix in the battery can be effectively and consistently controlled.
Further, it would be desirable to be able to accommodate the high-speed production of consolidated casings with the cathode mix while also having the capability to readily provide different amounts and densities of the cathode mix within the casings.
It would be advantageous if such an improved method and apparatus could operate in a substantially automated manner to feed the casings and cathode mix material to appropriate work stations for fabricating the consolidated assembly of the cathode material and dry cell battery casing. It would be beneficial if such an improved apparatus could also be employed with work stations carried on a rotating turret type device from which a casing feeding device could be driven.